1. Field of the Invention
This invention relates to novel [2]benzopyrano[4,3-b]pyridine derivatives, to processes for their preparation, to methods for using the derivatives and to pharmaceutically acceptable compositions of said derivatives.
More specifically, the present invention relates to novel 2,3,4,4a,6,10b-hexahydro-1H-[2]benzopyrano[4,3-b]pyridine derivatives possessing valuable pharmacologic properties. For example, these derivatives are useful diuretic agents at dosages which do not elicit undesirable side effects. The combination of this pharmacologic property with a low order of toxicity render the [2]benzopyrano[4,3-b]pyridine derivatives of the invention therapeutically useful.
2. Description of the Prior Art
A number of prior art reports dealing with benzopyranopyridines are available. For example, the [1]benzopyrano[3,4-c]pyridine ring system is described in the German Pat. No. 2,263,100, issued July 12, 1973 and by H. G. Pars and F. E. Granchelli in the U.S. Pat. No. 3,535,327, issued Oct. 20, 1970 and U.S. Pat. No. 3,632,595, issued Jan. 4, 1972. In addition, the fully unsaturated [2]benzopyrano[4,3-b]pyridin-6-one ring system is described by N. Dennis et al., J. Chem. soc., Perkin Trans. 1, 750(1974). The [2]benzopyrano[4,3-b]pyridine derivatives of the present invention are distinguished from the prior art compounds by having a fully saturated pyridine ring and by the nature of the substituents on the ring system. Furthermore, the compounds of the present invention are distinguished from the prior art compounds by their unique pharmacological properties.